Among the known solutions of the prior art, several character font representation formats have been developed.
None of these formats however propose an information management mechanism concerning the character fonts that have been previously selected by the designer or author of a graphical representation, for example a multimedia scene, in order to write text in the latter (a logo, mark, slogan etc. for example).
Among the most successful formats, more particularly dedicated to continuous loading (or “streaming”) of character fonts, parts 17 and 18 of the MPEG-4 standard (ISO/IEC 14496-17—“Information technology—Coding of audio-visual objects—Part 17 and ISO/IEC 14496-18—“Information technology—Coding of audio visual objects—Part 18) describe the mechanisms for enhancing character fonts and associating a content with a particular font in order to render text objects in an MPEG-4 scene, compressing and streaming character fonts of the “OpenType” type for transmission to a client terminal.
However, in the MPEG-4 standard, the management of character fonts takes place independently of the receiving terminal that is to render the MPEG-4 multimedia scene. The character font or fonts defined in the scene to be rendered are systematically transmitted to the receiving terminal, by a content or graphical scene server terminal, without any consideration as to knowing whether this receiving terminal has the capacity to receive and render the character font transmitted within the corresponding graphical scene (limited memory space for example).
Such an approach to the management of character fonts in the meaning of parts 17 and 18 of the MPEG-4 standard therefore does not enable a receiving terminal to effectively manage a set of fonts, nor even to characterize the latter by means of temporal properties, duration properties or characteristics relating to the multimedia contents to be rendered.
Conventionally therefore, the only techniques that make it possible to manage information relating to the character fonts previously defined for use in a graphical scene use basic permanent storage methods.
They suffer from a lack of flexibility usually resulting in the impossibility of downloading pieces of character fonts when all or some of the fonts stored in a client terminal become obsolete, or in difficulties in downloading new character fonts necessary for rendering a graphical scene referring to them, on terminals having limited memory, for example mobile communication terminals, telephones, digital television decoders, etc. In addition a terminal with limited memory does not always have the capacity to replace a character font that it is impossible for it to download or that has specific properties that are incompatible with it, with another character font with the closest properties to it and already stored in the terminal.
A method for coupling an unformatted stream of text data to a document presentation device (printer or screen) is also known through the IBM document (EP 0 119 396).
More precisely, the method presented in this document allows the selection of a character font from among a plurality of character fonts defined for various document presentation devices, according to character font identifiers to be used received in the text data stream.
However, the method described in this document is not adapted to manage portions of character fonts in a radio communication terminal.
Finally, the KUWATA et al document (US 2005/080839) describes a system for cataloguing character fonts on a network server and making them available to the computers connected thereto.
However, the system described in this document does not make it possible to manage portions of character fonts in a terminal, nor does it permit the updating of character fonts already catalogued, but supplies a backup catalogue of the character fonts accessible on a network.